Posted by Brigham and Women's Hospital April 2, 2015

Precision medicine involves testing DNA from patients’ tumors to identify the mutations or other genetic changes that drive their cancer.

Precision medicine is changing the way cancer is being studied and treated. Here are five important things to know.

1. Precision medicine can improve diagnosis and treatment.

Physicians have long recognized that the same disease can behave differently from one patient to another, and that there is no one-size-fits-all treatment. Precision cancer medicine makes diagnosis of cancer and other diseases more accurate and evaluates the specific genetic makeup of their tumors to select the safest and most effective treatments for them.

In cancer, precision medicine involves testing DNA from patients’ tumors to identify the mutations or other genetic changes that drive their cancer. Physicians then may be able to select a treatment for a particular patient’s cancer that best matches, or targets, the culprit mutations in the tumor DNA. Such therapies are becoming more widespread.

2. Not all cancer patients can or should receive precision medicine.

Targeted therapies may be appropriate for patients whose tumors have specific gene mutations that can be blocked by available drug compounds. These therapies aren’t indicated for patients whose tumors are driven by mutations that can’t be targeted by available drugs or lack mutations that have been associated with their disease.

According to the National Cancer Institute, a patient is a candidate for a targeted therapy only if he or she meets specific criteria, which vary depending on the disease. These criteria are set by the Federal Drug Administration (FDA) when it approves a specific targeted therapy.

3. Profile is one example of precision medicine in action.

The Profile project, launched in 2011 at Dana-Farber/Brigham and Women’s Cancer Center (DF/BWCC), is an example of precision medicine at work. All adult patients diagnosed with cancer can consent to have samples of their tumors analyzed for the presence of mutations and other cancer-related DNA abnormalities.

Since the inception of Profile, more than 13,500 genetic profiles – the particular set of mutations that drive a tumor – have been completed, and hundreds are added each month to the database.

4. Several cancers are already benefiting from precision medicine treatments.

More than ten years ago, researchers at Dana-Farber Cancer Institute and in Japan published a study showing that non-small cell lung cancer patients whose tumors had a mutated version of a protein called Epidermal Growth Factor Receptor (EGFR) responded dramatically to a drug that specifically targets the EGFR protein.

“Prior to this research, lung cancer treatment had not made much progress,” says Bruce Johnson, MD, chief clinical research officer at Dana-Farber Cancer Institute, who co-led the 2004 study with colleagues Pasi Jänne, MD, PhD, Matthew Meyerson, MD, PhD, and William Sellers, MD (now of the Novartis Institutes for BioMedical Research). “Today, patients with EGFR mutations who are treated with targeted drugs have a year of remission and survive an average of two to three years, with some making it to five years or more.”

Besides lung cancer, our researchers also have made precision cancer discoveries in triple-negative and HER2-positive breast cancer, colorectal cancer, neuroblastoma and other malignancies.

Clinicians at DF/BWCC currently use targeted therapies that pinpoint genetic mutations in a number of other cancers, including kidney, leukemia, and sarcoma.

5. Researchers are working on expanding precision medicine treatments.

New research in precision medicine is now focused on identifying a far greater number of mutations for a wider array of cancers, ultimately enabling clinicians to treat more cancers with targeted therapies in the future.

Dana-Farber Cancer Institute, Brigham and Women’s Hospital, Boston Children’s Hospital, the Broad Institute of MIT, and Harvard formed the Joint Center for Precision Cancer Medicine. The collaboration seeks to create “precision medicine pathways” for patients with advanced cancers and to speed the development of personalized therapies.

This post originally appeared on Insight, the blog of Dana-Farber Cancer Institute.